Dumb question FJ springs

[Harold1950]

I've seen the mileage of the vehicle (I guess) the FJ springs came off of referred to in numerous posts. Why? Do the springs weaken that much and need to be eventually replaced? If so, then I, like others, would want the low mileage springs. I thought that with normal use, they would last pretty much last the life of the vehicle barring any damage. Just curious. If this is in the wrong place, please feel free to move it........

 

[Dungeroo]

Spring Lingo

I just replaced mine ('07 SR5 4x) with a set from ebay that (supposedly) had only 800 odo miles on them from a suspension upgraded '08 FJ. Honestly, I would have bought them off of an FJ with more mileage but would have likely offered less. I got mine (with a set of 800 mi. struts and rear shocks) for $95 delivered to my door. I did not put the struts/shocks on .... they are sitting in my garage.

 

[fourwd1]

FJ coils is the flavor of the month, used to be LC coils, next month it may be Jeep TJ coils. Bottom line is, 4Runner rear springs haven't lasted long from day 1.
4Runner rear sag is infamous. Especially when they went to coils on the second gens.
They realized real quick the SUV market was headed to soccer mom's that wanted a smoother ride.